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<html lang="zh-CN">
    <head>
        <meta charset="UTF-8" />
        <title>12_变量-案例练习-交换2个变量-不通过第三个变量</title>
    </head>
    <body>
        <script>
            var a = 1;
            var b = 2;

            // a = 1 + 2;  3
            a = a + b;

            // b = 3 - 2;
            b = a - b;

            // a = 3 - 1; 
            a = a - b;

            console.log(a,b);




        </script>
    </body>
</html>